Children born to obese mothers with diabetes have more than four times the risk of developing autism spectrum disorder than children of healthy weight moms without diabetes, according to a new study at Johns Hopkins Bloomberg School of Public Health.
The findings, published in the journal Pediatrics, add to the growing body of information that the risk for autism likely develops before the child is even born.
“We have long known that obesity and diabetes aren’t good for mothers’ own health,” said study leader Xiaobin Wang, M.D., Sc.D., M.P.H., the Zanvyl Krieger Professor in Child Health at the Bloomberg School and director of the Center on the Early Life Origins of Disease.
“Now we have further evidence that these conditions also impact the long-term neural development of their children.”
Within the last several decades, the prevalence rates of autism have skyrocketed, with one in 68 U.S. children currently affected by it, according to the U.S. Centers for Disease Control and Prevention. Obesity and diabetes have also risen to epidemic levels in women of reproductive age over the same time period.
For the study, the researchers analyzed 2,734 mother-child pairs, a subset of the Boston Birth Cohort. The pairs were recruited at the Boston Medical Center at birth between 1998 and 2014. The researchers collected data on maternal pre-pregnancy weight and whether the moms had diabetes before getting pregnant or whether they developed gestational diabetes during pregnancy.
The researchers then tracked the children from birth through childhood via postnatal study visits and electronic medical records. In total, 102 children had been diagnosed with autism spectrum disorder over the course of the study.
The researchers found that children whose mothers who were both diabetic and obese were more than four times as likely to develop autism compared to children born to normal weight mothers without diabetes.
“Our research highlights that the risk for autism begins in utero,” said co-author M. Daniele Fallin, Ph.D., chair of the Bloomberg School’s Department of Mental Health and director of the Wendy Klag Center for Autism and Developmental Disabilities. “It’s important for us to now try to figure out what is it about the combination of obesity and diabetes that is potentially contributing to sub-optimal fetal health.”
Prior research has suggested a link between maternal diabetes and autism, but this is believed to be the first study to look at both obesity and diabetes together as a risk factor.
Along with pre-conception diabetes, children of obese mothers who had developed gestational diabetes during pregnancy were also at a significantly higher risk of developing autism.
Exactly why obesity and diabetes contribute to autism risk isn’t completely understood. Earlier research has found that maternal obesity may be associated with inflammation in the developing fetal brain. Other studies suggest obese women have less folate, a B-vitamin vital for human development and health.
The researchers say that women of reproductive age who are thinking about having children need to be cautious of their weight and overall health, not only for themselves, but because of the implications it could have on their future children. Better diabetes and weight management could have lifelong impacts on mother and child, they say.
“In order to prevent autism, we may need to consider not only pregnancy, but also pre-pregnancy health,” Fallin says.